U.S. patent number 6,786,520 [Application Number 10/298,164] was granted by the patent office on 2004-09-07 for motor vehicle bumper and motor vehicle.
This patent grant is currently assigned to Dynamit Nobel Kunststoff GmbH. Invention is credited to Steffen Burkhardt, Dietmar Preissler, Anton Sautner.
United States Patent |
6,786,520 |
Burkhardt , et al. |
September 7, 2004 |
Motor vehicle bumper and motor vehicle
Abstract
The invention relates to a motor vehicle bumper with an inside
bumper unit which can be fastened to a vehicle body and a bumper
outside unit which is fastened section-wise to the bumper inside
part. According to the invention the inside bumper unit supports
the outside bumper unit solely in the area of its sill portion
which is to be arranged under a vehicle trunk lid. Use for
lightweight bumpers for motor vehicles.
Inventors: |
Burkhardt; Steffen (Herrenberg,
DE), Preissler; Dietmar (Hagenbuch, DE),
Sautner; Anton (Treuchtlingen, DE) |
Assignee: |
Dynamit Nobel Kunststoff GmbH
(Weissenburg, DE)
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Family
ID: |
7706323 |
Appl.
No.: |
10/298,164 |
Filed: |
November 15, 2002 |
Foreign Application Priority Data
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Nov 20, 2001 [DE] |
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101 56 892 |
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Current U.S.
Class: |
293/102; 293/117;
293/120 |
Current CPC
Class: |
B60R
19/24 (20130101); B60R 2019/1886 (20130101); B60R
2021/0011 (20130101) |
Current International
Class: |
B60R
19/24 (20060101); B60R 21/00 (20060101); B60R
19/18 (20060101); B60R 019/02 () |
Field of
Search: |
;293/102,120,133,134,117,118,155,119,136,128,132,107,126,109,93
;414/462 ;224/42.21,521 ;428/31 ;5/94 ;296/136.03,98,93
;362/549,496 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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36 19184 |
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Dec 1987 |
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DE |
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2 256 852 |
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Jan 1974 |
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FR |
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2000 326806 |
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Nov 2000 |
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JP |
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Primary Examiner: Patel; Kiran
Attorney, Agent or Firm: Fulbright & Jaworski L.L.P.
Claims
What is claimed is:
1. A motor vehicle bumper having an interior bumper unit which can
be affixed to a motor vehicle body, and an exterior bumper unit
which can be affixed section-wise to the interior bumper unit,
wherein the interior bumper unit supports the exterior bumper unit
exclusively in the rear sill portion of the exterior bumper unit to
be arranged below a vehicle trunk lid, wherein the interior bumper
unit has a clip strip running in the transverse direction of the
vehicle, into which an edge of the exterior bumper unit facing the
vehicle body is clamped.
2. The motor vehicle bumper according to claim 1, wherein the
interior bumper unit has a ribbed structure.
3. The motor vehicle bumper according to claim 1, wherein the
interior bumper unit is provided with cutouts.
4. The motor vehicle bumper according to claim 1, wherein the
interior bumper unit runs substantially along the vehicle body,
from a first fastening means for its fastening to the vehicle body,
toward the still portion, and beneath the area of the sill portion
it has a balcony-like projection which extends in the lengthwise
direction of the vehicle.
5. The motor vehicle bumper according to claim 1, wherein said clip
strip is arranged directly underneath the trunk lid.
6. The motor vehicle bumper according to claim 5, wherein the clip
strip is provided with clamping ribs disposed substantially
perpendicular to the transverse direction of the vehicle.
7. The motor vehicle bumper according to claim 1, wherein a
deformation body is fastened to the vehicle body underneath the
interior bumper unit and is covered by the exterior bumper unit.
Description
The invention relates to a motor vehicle bumper with a interior
bumper unit which can be fastened to a vehicle body and an exterior
bumper unit fastened section-wise to the interior bumper unit.
German Patent 27 02 691 C3 has disclosed a motor vehicle bumper
with an interior motor vehicle bumper unit and an exterior bumper
unit. To affix the exterior bumper unit the latter is pushed over
the interior unit and fastened to it with snap fasteners. The
exterior bumper unit consists of plastic. For the support of the
exterior bumper unit the latter is supported on its full surface by
the interior part below its upper as well as its lower edge. The
interior bumper unit is configured as a rigid support which is
fastened to a vehicle with mountings of energy-absorbing
construction.
A motor vehicle bumper disclosed in European Patent 0 430 665 B1
(FIG. 8) has an exterior unit and an interior unit supporting the
exterior unit. In normal operation, a heavy stress on the bumper is
to be expected only in the area of the rear sill portion. Since
only this heavily stressed part is supported, a saving of material
and weight can be achieved in comparison with conventional bumpers
whose interior units support an exterior unit over the entire width
of the upper and lower side.
A saving of weight and material is to be achieved by the invention
in a motor vehicle bumper.
For this purpose, according to the invention, a motor vehicle
bumper is provided with an interior bumper unit which can be
fastened to a vehicle body, and an exterior bumper unit which can
be fastened section-wise to the interior bumper unit, wherein the
interior bumper unit support the exterior bumper unit only at rear
sill portion of the exterior bumper unit, which is to be situated
beneath a motor vehicle's trunk lid.
In normal operation of the vehicle great stress upon the bumper is
to be expected only in the area of the rear sill. Since only this
latter, highly stressed area is supported, a saving of material and
weight in comparison with conventional bumpers whose interior
portions support an external portion over the entire width of the
upper or lower side.
In further embodiment of the invention, the interior bumper unit
has a ribbed structure.
By these measures a very great stiffness can be achieved,
accompanied by a saving in weight.
It is likewise advantageous to provided the interior bumper unit
with cutouts.
In this manner, material and weight can be saved without impairing
the stiffness of the interior part.
In further embodiment of the invention, the interior bumper unit
runs from the first fastening means for fastening the vehicle body
toward the rear sill portion, substantially along the vehicle body,
and has underneath the sill portion at least one balcony-like
projection reaching in the direction of the length of the
vehicle.
By these measures space can be created for a plastic deformation of
the exterior bumper unit as well as for any energy-absorbing
components. Furthermore, in the space available below the balcony,
components such as sensors, antennas or the like can be disposed.
Nevertheless, the area of the rear sill portion is supported. An
additional saving of material and weight can be achieved by
balconies disposed side by side in the transverse direction of the
vehicle.
In further embodiment of the invention the interior bumper unit has
a clip strip running transversely across the vehicle, into which an
edge of the exterior bumper unit facing the vehicle body is
clipped. Advantageously, the clip strip is provided with retaining
ribs running in the lengthwise direction of the vehicle and
substantially perpendicular to the transverse direction of the
vehicle.
By these measures an edge of the exterior bumper unit, provided if
desired with catch means, can be held. By means of the clip ribs a
secure fastening as well as a saving of material as compared with a
full-surface clip strip. For the adjustment of the fastening, clip
ribs are easier to adapt than a full-surface ramp or strip. This is
especially advantageous if the clip strip is made of
injection-molded plastic and an injection mold is to be adapted to
it.
The problem on which the invention is based is also solved by a
motor vehicle with a bumper according to the invention in which a
deformation body is fastened to the vehicle body underneath the
interior bumper unit and is covered by the exterior bumper
unit.
This division into deformation body and interior unit makes it
possible to select the materials of the interior unit and
deformation body according to their function. For example, the
interior unit can consist of injection-molded plastic while the
deformation body is made of aluminum.
Additional features and advantages of the invention will be found
in the claims and in the following description of a preferred
embodiment of the invention, in conjunction with the drawings,
wherein
FIG. 1 is a fragmentary sectional view of a bumper according to the
invention, applied to a motor vehicle,
FIG. 2 another fragmentary sectional view of the interior bumper
unit,
FIG. 3 a perspective view of the interior bumper unit of FIG. 1,
and
FIG. 4 another perspective view of the interior bumper unit of FIG.
1.
In the fragmentary sectional view of FIG. 1 there is represented a
portion of motor vehicle's bumper 10 pursuant to the invention,
which is affixed to a motor vehicle body 14. Only a portion of the
exterior bumper unit 16 is shown, and is fastened to the interior
bumper unit 12 by the fact that an edge of the exterior bumper unit
16 has been inserted into a clip strip 18 of the interior bumper
unit. The clip strip 18 of the interior bumper unit 12 has a notch
into which a catch projection 20 resiliently disposed on the
exterior bumper unit is engaged. An opening in the clip strip 18 to
accommodate the edge of the exterior bumper unit is defined on its
bottom by clip ribs 22 arranged parallel to the length of the
vehicle and at right angles to its width, only one of them being
seen in FIG. 1. A strip-like projection 24 forms the upper
boundary, in FIG. 1, of the opening in the clip strip 18. The
strip-like projection 24 bears the notch for engaging the catch
projection 20 of the exterior bumper unit.
Upon the insertion of the front edge of the exterior bumper unit 16
into the clip strip 18, the latter is first guided by the clip ribs
22 and the strip-like projection 24. As the insertion of the
exterior bumper unit 16 continues, the catch projection 20 snaps
into the notch of the strip-like projection 24, and furthermore the
exterior bumper unit becomes gripped between the clip ribs 22 and
the strip-like projection 24.
The horizontal section of the exterior bumper unit 16 represented
in FIG. 1 forms the area of a rear sill portion which is situated
beneath a merely indicated trunk lid 26. When a vehicle is loaded,
this sill portion area is subjected to stress, for example when
goods are set down on the sill portion area. To stabilize the rear
sill portion area, the interior bumper unit 12 has a balcony-like
projection 28 running in the direction of the vehicle's length
underneath the rear sill portion area. The projection 28 consists
of a rib disposed parallel to the vehicle's length and
perpendicular to the width of the vehicle and provided with a
perpendicular stiffening rib 30. Above the stiffening rib 30 the
projection 38 merges with the clip rib 22.
The interior bumper unit is connected to the vehicle body 14 by a
bolt 32 indicated schematically. The interior bumper unit 12
extends from the bolt 32 along the vehicle's body 14 and then turns
away from the vehicle body 14 in the area of the rear sill portion
underneath the sill portion area of the exterior bumper unit 16. A
deformation space is thereby created between the exterior bumper
unit 16 and the vehicle body 14, which can be used for energy
absorption during a collision of the vehicle.
As it is shown in FIG. 2, a deformation body 34 is arranged within
this space between the exterior bumper unit 16 and the vehicle body
14. The deformation body 34 consists of a hollow aluminum profile
and is fastened by means of supports indicated by broken lines to
the vehicle's body. By separating the deformation body 34, the
energy-absorbing hollow profile and bumper 10, the latter can
better compensate for tolerances of the car body 14, since the
hollow profile does not add rigidity to the bumper 10.
In FIG. 1 can be seen the ribbed configuration of the interior
bumper unit 12 which has a great stiffness due to components of
large area arranged perpendicular to one another, such as the
projection 28 and the rib 30. To save weight and material the
surfaces can be provided partially with cutouts 36.
A perspective view of the interior bumper unit 12 as seen from the
vehicle body is represented in FIG. 3. Easy to see is the ribbed
configuration of the interior bumper unit with a curved plate 40,
and ribs 42 arranged perpendicular thereto. Plate 40 is provided
with numerous cutouts 36. Also to be seen are two cutouts 44 with
hooks which are provided in order to hold plates provided with
bolts for fastening the interior bumper unit 12 to the vehicle
body. The interior bumper unit 12 extends only over the width of
the back sill portion in the transverse direction of the vehicle.
The exterior bumper unit is thus supported only locally, so that
the interior bumper unit 12 can be made substantially smaller and
lighter in comparison with conventional interior bumper units.
The perspective view in FIG. 4 shows the interior bumper unit 12 as
seen from the side of the exterior bumper unit. Shown are the
balcony-like projections 28 for supporting the rear sill portion of
the exterior bumper unit. Over the length of the rear sill portion
running transversely across the vehicle's width a total of ten
projections 28 are arranged in pairs. Two projections 28 of a pair
are joined together by ribs 30. Thus each pair of balcony
projections 28 in direction Z, i.e., in the direction of the height
of the vehicle, forms an extremely stable combination and they are
deformable, yet energy-absorbing, in direction X, i.e., in the
direction of the vehicle's length. On the rib 30, in the area of
each balcony-like projection, a clip rib 22 is disposed, which
extends from the clip strip 18 all the way to the end part of the
projection 28. Furthermore, shorter clip ribs 46 are disposed on
the rib 30 parallel to the clip ribs 22. While the clip ribs 22 are
provided in their forward area near the balcony-like projection 28
for the introduction of an edge of the exterior bumper unit into
the clip strip 28, the section of clip ribs 22 lying under the
projection 24 of the clip strip 22 as well as the clip ribs 46
lying also underneath the projection 24 serves to grip the edge of
the exterior bumper unit tightly in the clip strip 18.
As it has been explained, the interior bumper unit 12 supports the
exterior bumper unit only in the area of the rear sill portion. As
it is indicated in FIG. 4, the interior bumper unit 12 terminates
in the transverse direction of the vehicle in the area of the
exterior bumper unit, since the rear sill portion merges with an
upwardly bent area. The support of the rear sill portion by the
interior bumper unit 12 thus ends in an area wherein stress is no
longer applied to the bumper in daily operation, or in which the
exterior bumper unit is given sufficient inherent stiffness by its
shape. The upwardly curved areas adjoining the rear sill portion
area on the right and left are indicated in broken lines in FIG. 4
and indicate the shape of a vehicle trunk lid arranged above the
rear sill portion area.
* * * * *